Abstract: The kinetics of synergistie extraction of U(Ⅵ) with TOA-TOPO in n-hexane have been investigated using the single drop technique.The extraction rate is found to increase with the addition of synergtst TOPO. Tke effects of the concentrations of U(Ⅵ) , H+, TOA, TOPO, temperature on the extraction rate are studied and apparent activation energy is calculated. .The rate-controlling step and a kinetic equation are suggested.